This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-294313, filed on Sep. 27, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an apparatus and a method which are applied to exposure by a charged beam.
2. Description of the Related Art
Electron beam exposure of a character projection (CP) system is a method of forming an about several micrometers character projection (CP) pattern in a second aperture mask, and using the character projection pattern to perform exposure. The character projection (CP) system is regarded as promising means for enhancing throughput in the electron beam exposure.
Usually, the number of character projection patterns (CP pattern number) is about five. A conventional operation for preparing a table regarding shape and placement of the CP pattern is performed by operator""s manual input.
However, the CP pattern number tends to increase in order to enhance the throughput of an electron beam exposure apparatus. When the number of types of CP patterns exceeds 100, it is remarkably intricate to perform the table preparing operation by the operator""s manual input. Moreover, time required for the operation, failure of exposure by operator""s input mistake, and the like remarkably deteriorate productivity in the electron beam exposure.
On the other hand, since thickness of a substrate with the CP pattern formed thereon is as small as about several micrometers, a defect, and the like are possibly generated in the CP pattern during handling. When the pattern having the defect is used to perform the exposure, a pattern different from a desired pattern is transferred onto a wafer. Therefore, productivity in the electron beam exposure is remarkably deteriorated.
As described above, the preparing operation of the table regarding the CP pattern has heretofore been performed by the operator""s manual input. This is a factor remarkably deteriorating the productivity in the electron beam exposure and another charged beam exposure.
Moreover, when the CP pattern having the defect is used to perform the exposure, a target pattern cannot be obtained. This is also a factor remarkably deteriorating the productivity in the charged beam exposure.
According to a first aspect of the present invention, there is provided an apparatus applied to exposure by a charged beam, comprising: a pattern information acquiring section acquiring information on a character projection pattern formed in a character projection aperture mask; a first information storing section storing information on a reference pattern; and an identifying section identifying a shape of the character projection pattern by comparing the information on the character projection pattern with the information on the reference pattern.
According to a second aspect of the present invention, there is provided a method applied to exposure by a charged beam, comprising acquiring information on a character projection pattern formed in a character projection aperture mask; and identifying a shape of the character projection pattern by comparing the information on the character projection pattern with information on a reference pattern.